Short answer: the safest time to cross the Bay of Biscay by yacht is May to August, when offshore gales are rare. The most common crossing runs from Brest or Camaret in Brittany to A Coruña in Galicia, about 360 nautical miles or roughly three days for an average yacht. The keys to a good crossing are a reliable five-day forecast, staying clear of the continental shelf in strong onshore winds, and getting past Cape Finisterre before the weather turns.
The Bay of Biscay has a fearsome reputation, and it is not unearned. But for a well-prepared yacht and a crew who choose their weather window carefully, it is usually a straightforward passage. This guide is written by the delivery captains at Nordic Crew Worldwide, who cross Biscay every season when they move yachts from Scandinavia and Northern Europe down to the Mediterranean.
Why the Bay of Biscay has its reputation
Three things make Biscay different from most European coastal passages:
- The continental shelf. About 60–100 miles offshore, the seabed rises sharply from more than 3,000 m to around 100 m. When strong onshore winds or a big Atlantic swell hit that step, the sea becomes short, steep and confused.
- Atlantic swell. Swell generated by distant low-pressure systems rolls into the bay. Sea state can be far worse than the local wind suggests — a Force 6 on top of a large swell can produce 5 m seas.
- Few all-weather harbours. South of Brest, much of the French and northern Spanish coast offers limited shelter in onshore weather, and some harbour entrances become dangerous in a big swell.
The three ways to cross Biscay
| Route | Typical passage | Distance | Best for |
|---|---|---|---|
| Direct crossing | Brest / Camaret → A Coruña or Viveiro | ~360 nm | Most yachts; slower or short-handed crews |
| Offshore route | Falmouth / Plymouth → Baiona, staying west of 10°W | ~550 nm | Fast, fully crewed boats; avoids the shelf |
| Coastal hop | Along the French coast, then across to Gijón, Santander or Bilbao | Day hops | Owners with time; boats that prefer short legs |
For most yacht deliveries we choose the direct crossing from Brittany. It keeps the time offshore short, avoids the busiest shipping lanes, and leaves several landfall options on the Galician coast if the forecast changes.
Best time to cross
- May to August: the most settled period. Offshore gales are extremely rare in June and July, although inshore gales around the Spanish capes still occur.
- September: still workable, but weather windows become shorter and less predictable.
- October to April: possible, but windows can take a long time to appear. A delivery in this period needs a flexible schedule and an experienced crew.
If you are planning to move a yacht from Northern Europe to the Mediterranean, aim to have it in Brittany ready to cross by early summer. See our Scandinavia to Mediterranean route guide for the full passage plan.
Choosing a weather window
- Get a reliable five-day forecast. The crossing takes about three days; the extra time is your buffer if the boat is slower than planned or the weather changes faster than forecast.
- Compare two models. Check both ECMWF and GFS, plus the shipping forecast, NAVTEX and GRIB files. If they disagree strongly, wait.
- Avoid leaving straight after a depression. Leftover swell meeting a fresh breeze over the shelf is exactly what makes Biscay uncomfortable.
- Watch the pressure. A fall of about 6 hPa in three hours is a warning sign of strong wind on the way.
- Motor through calms. If the wind drops, keep moving so you don’t lose the window.
- Get past Finisterre. When heading south, aim to round Cape Finisterre before the next system arrives — otherwise you can be stuck waiting on Spain’s north coast.
Hazards to plan around
- Traffic separation schemes off Ushant and Cape Finisterre. Merchant ships move fast and may not see a yacht — keep a proper lookout and use AIS.
- Fishing boats working the edge of the continental shelf, often at night.
- Accelerated winds around Capes Ortegal and Finisterre, where north-easterlies can quickly reach gale force.
- Orca interactions off Galicia, Portugal and the Strait of Gibraltar. Read our guide to orca interactions off Spain and Portugal before planning the onward route.
- The Costa da Morte between A Coruña and Finisterre, which should be avoided in onshore swell.
Preparing the boat for Biscay
Biscay is often the first real offshore test on a delivery south, and it will find any weakness in the boat. Before departure we check:
- Engine service, clean fuel and spare filters — rough seas stir up sediment in fuel tanks
- Rigging, steering, autopilot and reefing systems
- Jacklines, harnesses and lifejackets for every crew member
- Life raft, EPIRB and grab bag in date and ready
- Everything below decks stowed for heavy weather
Our full owner’s checklist for preparing a yacht for delivery covers documents, insurance and the handover too.
How a professional delivery crew handles Biscay
On a Nordic Crew Worldwide delivery, Biscay is planned before the boat even leaves its home port. Our captains — officers recruited from the commercial maritime fleet — use professional weather routing, set a watch system that keeps the crew rested, and only leave when the window gives a clear margin. You receive position and ETA updates during the crossing, so you always know where your yacht is.
See our yacht delivery packages or request a free quote for your route.
Related guides
- Strait of Gibraltar by yacht: tides, winds and when to go
- Mediterranean winds explained
- Weather routing for yacht deliveries
- Yacht delivery calendar
- Yacht delivery along Portugal
- Sailing from the UK to the Med
Frequently asked questions
When is the best time to cross the Bay of Biscay?
May to August is the most settled period, and offshore gales are extremely rare in June and July. Crossings in autumn and winter are possible but weather windows can take much longer to appear.
How long does it take to cross the Bay of Biscay by yacht?
The direct crossing from Brest or Camaret to A Coruña is about 360 nautical miles and takes roughly three days for an average cruising yacht. The longer offshore route from Falmouth or Plymouth to Baiona is about 550 nautical miles.
Why is the Bay of Biscay dangerous?
The continental shelf rises steeply from more than 3,000 m to around 100 m, which makes Atlantic swell short and steep in strong onshore winds. There are also few all-weather harbours south of Brest, busy shipping lanes and accelerated winds around the Spanish capes.
Can a professional crew deliver my yacht across Biscay?
Yes. Nordic Crew Worldwide delivers yachts across Biscay every season as part of routes from Scandinavia and Northern Europe to the Mediterranean, with professional weather routing and regular position updates to the owner.